为iOS App增加启动渐变效果

转自：http://blog.csdn.net/jasonblog/article/details/8029081

由于目前苹果没有支持该功能，所以只能自己在App启动后做一个过度效果：

[cpp] view
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- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions  

{  

    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];  

    // Override point for customization after application launch.  

    self.viewController = [[[ViewController alloc] initWithNibName:@"ViewController" bundle:nil] autorelease];  

    self.window.rootViewController = self.viewController;  

    [self.window makeKeyAndVisible];  

      

    UIImageView *splashScreen = [[[UIImageView alloc] initWithFrame:self.window.bounds] autorelease];  

    splashScreen.image = [UIImage imageNamed:@"Default"];  

    [self.window addSubview:splashScreen];  

      

    [UIView animateWithDuration:1.0 animations:^{  

        CATransform3D transform = CATransform3DMakeScale(1.5, 1.5, 1.0);  

        splashScreen.layer.transform = transform;  

        splashScreen.alpha = 0.0;  

    } completion:^(BOOL finished) {  

        [splashScreen removeFromSuperview];  

    }];  

      

    return YES;  

}